1. Field of the Invention
The present invention relates to an implantable electrical stimulator, and more particularly to a flexible implantable electrical stimulator using a flexible circuit board.
2. Description of the Related Art
Electrical stimulator combines theories of Chinese traditional Point Percussion Therapy and TENS (Transcutaneous Electrical Nerve Stimulation) by using finite electrical current to stimulate particular points or muscles for reaching the effects of strong and health, that is, by using electrical current with proper frequency to stimulate nerves, muscles and cells continuously and gently, which can activate the self-recovering mechanism of body. There are two kinds of therapies clinically, TENS and EMS (Electrical Muscle Stimulation).
The electrical stimulators are widely used in rehabilitation, and due to the recent breakthrough of microelectronic technique, MEMS (Micro-Electro-Mechanical Systems), bio-material and biocompatible package technique, it makes electrical stimulators to be a miniature and implantable type.
A well-known electrical stimulator with biocompatible package encases all electrical components by a glass shell to prevent body fluid from infiltration. However, the glass package is a such hard package structure, if it is implanted into human's muscle structure, its metal materials therein will be directly contact with inner tissue of human body once it is broken due to the extrusion from muscular activities, and further releasing toxic materials, and can not achieve the purpose to be biocompatible.